To provide a storage battery having a larger capacity and outputting a higher voltage, a plurality of battery modules is coupled in series and in parallel.
PTL 1 points out that, when a single central microprocessor is used to monitor all voltage values of a plurality of batteries coupled in series to configure a battery module, an analog level shift circuit is required for converting a voltage difference between a reference potential point for a voltage detection IC provided for each battery and a grounding reference point for the central microprocessor, so that the more batteries increase in number, the more consumption power increases.
To solve this problem, PTL 1 describes that an individual detection module having a function for detecting a voltage value and a function of a microprocessor is provided for each battery, and each individual module is coupled to the central microprocessor via an isolator.